GLUT 4 depletion may be one mechanism responsible for insulin resistance in non-insulin-dependent diabetes mellitus (NIDDM). The PI will obtain muscle from 3 different muscle groups from NIDDM subjects. The hypotheses are that 1) GLUT 4 content will vary as a function of muscle group in individual patients; 2) GLUT 4 content will be higher in muscles composed mainly of oxidative muscle fibers; 3) patients who are less insulin sensitive will have a corresponding degree of GLUT 4 depletion in all muscles. We have demonstrated that Type II diabetics have muscle-specific GLUT 4 variability. We are currently undertaking analysis of potential GLUT 4 translocation defects in these muscle groups.